1. Field of the Invention
The present invention relates to reclosable plastic bags having slide zippers. More particularly, the present invention relates to a method and apparatus for making slide-zippered reclosable bags on form-fill-seal (FFS) machines.
2. Description of the Prior Art
Methods and apparatus for manufacturing reclosable plastic bags on FFS machines using reclosable zippers are well-known in the art. These prior art methods and apparatus, however, are limited to interlocking zippers which are directly opened and closed by the hands of the bag user and are not designed for the utilization of a slider for opening and closing the zipper.
The method and apparatus of the present invention, on the other hand, relate specifically to reclosable bags having a slide zipper. Reclosable bags having slide zippers are generally more desirable to consumers than bags which have traditional interlocking zippers since it is much easier for the user to open and close bags having a slide zipper. It is thus commercially highly desirable and advantageous to provide a method of and apparatus for manufacturing slide-zippered reclosable plastic bags in a continuous, automated process.
Slide zippers for use with plastic bags are well known in the reclosable fastener art. Examples of conventional slide zippers can be found in U.S. Pat. Nos. 5,007,143, 5,008,971, 5,131,121 and 5,664,299. Typical slide zippers comprise a plastic zipper having two interlocking profiles and a slider for opening and closing the zipper. The slider straddles the zipper and has a separator at one end which is inserted between the profiles in order to force them apart, that is, the separator plows between the profiles forcing them to disengage. The other end of the slider is sufficiently narrow to be able to close the zipper.
Recently, a new type of slider zipper has been developed which, as discussed fully below, improves on prior art slide zippers and includes features which facilitate the manufacture of bags in automated form fill processes.
It is therefore the object of the present invention to provide a unique and novel method and apparatus for making slide-zippered bags on an FFS machine.